最近几天我遇到了一些奇怪的问题。当我更新我的 apache2.conf 并想使用重新启动我的 apache2 时，service apache2 restart一如既往地没有输出。尝试解析我的网站会出现 Cloudflare 521 错误（Web 服务器已关闭）。当我尝试apachectl stop（提示未找到正在运行的 pid）时，apachectl start它又恢复正常了。
service apache2 stop之后就service apache2 start不起作用了
/var/log/apache2/error.log：
[Sun Apr 30 22:53:43.646337 2017] [mpm_prefork:notice] [pid 9619] AH00163: Apache/2.4.10 (Debian) OpenSSL/1.0.1t configured -- resuming normal operations
[Sun Apr 30 22:53:43.646450 2017] [core:notice] [pid 9619] AH00094: Command line: '/usr/sbin/apache2'
[Sun Apr 30 23:01:02.678916 2017] [core:error] [pid 9624] [client 162.158.XX.XX:34442] AH00124: Request exceeded the limit of 10 internal redirects due to probable configuration error. Use 'LimitInternalRecursion' to increase the limit if necessary. Use 'LogLevel debug' to get a backtrace., referer: https://ts.naspyy.eu/
[Sun Apr 30 23:38:29.531546 2017] [mpm_prefork:notice] [pid 9619] AH00169: caught SIGTERM, shutting down